IMAGE CODER AND IMAGE DECODER

摘要

PROBLEM TO BE SOLVED: To provide an image coder and an image decoder that can transmit/ record an image with high resolution by using a transmission/recording medium for an image with low resolution. SOLUTION: The image coder and the image decoder is provided with a 1st band limit means that extracts a band limit luminance signal YA from an input luminance signal Y1, a 2nd band limit means that extracts a band limit color difference signal CA from an input color difference signal C1, a signal division means that divides the band limit luminance signal YA into a luminance main signal YM and a luminance reinforcement signal YE, a signal generating means that selects the signal YM for a 2nd luminance signal Y2 and composites the band limit color difference signal CA and the luminance reinforcement signal YE to provide a 2nd color difference signal G2, a signal separate means that separates the 2nd color difference signal C2 into a decoded color difference signal C1' and a decoded luminance reinforcement signal YE', and a luminance signal decoding means that generates a decoded luminance signal Y1' resulting from composting the 2nd luminance signal Y2 and the decoded luminance reinforcement signal YE'.